When the maximal dose of the blinded solution is achieved, an open label perfusion of norepinephrine can be added to achieve the desired blood pressure. Epinephrine or vasopressin may be used only as rescue therapy. Weaning of vasopressor agents will begin by weaning of the open label norepinephrine, followed by weaning of the blinded solution. In case of recurrence of hypotension, the blinded solution will be resumed first (maximal dose with the 2 agents will be 20 µg/kg.min for dopamine and 0.19 mcg/kg.min for norepinephrine) and if needed an open label solution of norepinephrine may be added. Weaning of the vasopressors will be performed as previously described.